Keyboard Events cross browser - keydown/keyup

HTML

<p>press ctrl + a</p>

JavaScript

(function () {
    //keydown event
    //keyup event 
    //keypress event (does not fire on modifier keys space, shift, etc designed for user input primarily)

    //crossBrowser Events util object
    var util = {
        addEvent: function (el, type, fn) {
            if (typeof addEventListener !== "undefined") {
                el.addEventListener(type, fn, false);
            } else if (typeof attahcEvent !== "undefined") {
                el.attachEvent("on" + type, fn);
            } else {
                el["on" + type] = fn;
            }
        },
        remove: function (el, type, fn) {
            if (typeof removeEventListener !== "undefined") {
                el.removeEventListener(type, fn, false);
            } else if (typeof detachEvent !== "undefined") {
                el.detachEvent("on" + type, fn);
            } else {
                el["on" + type] = fn;
            }
        },
        getTarget: function (e) {
            if (typeof e.target !== "undefined") {
                return e.target;
            } else {
                return e.srcElement;
            }
        },
        preventDefault: function (e) {
            if (typeof e.preventDefault !== "undefined") {
                e.preventDefault();
            } else {
                e.returnValue = false;
            }
        },
        getCharCode: function (e) {
            if (typeof e.charCode === "number") {
                //standard browser we get .charCode    
                return e.charCode;
            } else {
                //for legacy IE it is .keyCode
                return e.keyCode;
            }
        }
    }
    /* --------------------------------------------*/

    var txtIn = document.getElementById("txtinput");

    util.addEvent(document, "keydown", function (e) {
        //do not need the cross browser code to retrieve it
        // works in every browser with some differences
        var code = e.keyCode;
       // alert(code);
        //will...